Alpha particles are emitted by a wide range of heavy nuclei, which are responsible for a large proportion of radioactive materials required to be monitored. Furthermore, alpha particles are potentially the most damaging type of radiation to biological tissue due to their high mass and relatively high energy. However, alpha particles are difficult to detect since they are readily absorbed in materials and biological tissue, and even in air can travel no more than a few centimeters from the radioactive source material. Thus, typical detectors for alpha particles have to be brought very close to the scanned items, which makes scanning slow, cumbersome, or even impractical in many common environments.
As a result, the ability to scan fast, reliably, and specifically for alpha particles especially in relatively confined complex-geometry terrain, e.g. ground vehicles, maritime vessels, shipping containers, and aircraft, would be a valuable asset. Furthermore, in a forensic sense, it would be useful to provide a system capable of determining if a nuclear material was present at some certain point in the past.
The system disclosed here provides for the detection of nuclear materials and/or potentially irradiated objects through evaluation of oxygen-17 (17O) quantities in a local atmosphere. The local atmosphere sampled is in contact with the material or object under evaluation and typically comprises air. The 17O quantity in the local atmosphere is determined using mass spectroscopy, nuclear resonance magnetic imaging, gas chromatography, or some other method, and deviations in 17O quantity relative to an expected baseline are treated as indicative that a nuclear reaction converting nitrogen-14 (14N) to 17O has occurred or is occurring.
These and other objects, aspects, and advantages of the present disclosure will become better understood with reference to the accompanying description and claims.